Method for operating a spinning station of a spinning machine, and spinning machine

ABSTRACT

A method for operating a spinning station of a spinning machine includes, during a downtime of the spinning station, performing one or both of: driving and stopping the opening roller at least one time by means of an individual drive configured with the opening roller, or driving the opening roller at a minimum rotation speed by means of the individual drive.

FIELD OF THE INVENTION

The present invention relates to a method for operating a spinningstation of a spinning machine, in which a fiber material is opened intoindividual fibers by means of an opening unit and the individual fibersare spun into a yarn by means of a spinning device. The opening unitincludes an opening roller, which is rotatably mounted in an openinghousing and is drivable by means of an individual drive. The spinningdevice is connected to a negative pressure channel of the spinningmachine and acted upon by negative pressure, and the opening housingbeing connected to the spinning device via a feed duct.

BACKGROUND

Opening rollers are known in various embodiments from the prior art andare used to open a fiber material into loose individual fibers, whichfiber material has been presented to the spinning device and is in theform of a continuous sliver. In open-end spinning, only individualfibers can be processed and pieced onto an open end of the yarn. Forthis purpose, the rotatably driven opening rollers are provided with acard clothing, which extracts the individual fibers from the presentedsliver and conveys the individual fibers to a feed duct, from where theindividual fibers are supplied to the spinning device.

For various reasons, fibers can accumulate at the opening roller. Thefibers cling at various points between the rotating opening roller andthe walls of the opening roller housing surrounding the opening roller.This can slow down the movement of the opening roller and lead up to acomplete blockage of the opening roller.

DE 34 17 567 A1 describes that individual fibers can travel past the endface of the opening roller, in particular due to the helical arrangementof the card clothing, and become clamped in the region between the endface of the opening roller and the housing wall situated opposite theend face. To avoid these problems, DE 34 17 567 A1 provides that anadditional air flow is introduced into the opening roller housing, whichblows the fibers back into the region of the card clothing.

DE 33 41 279 A1 also describes a suction effect between the end faces ofthe opening roller and the housing wall. To solve the problem, it isprovided that a scraper collecting groove is provided at the wall of theopening housing situated opposite the end face of the opening roller.

Similarly, DE 23 29 223 A1 describes that an air flow through theopening roller housing arises despite lateral covers of the openingroller, which project over the card clothing. The air flow is caused bya pressure gradient between the fiber supply side and the fiberdischarge side, which is connected to the fiber feed duct. Anaccumulation of fibers is also to be avoided here by means of a certaingeometric shape.

One aspect that is common to the aforementioned publications is that theopening roller is driven together with the other opening rollers by acentral drive via a machine-length tangential belt. These types ofspinning machines usually include a service device, which is movablealong the workstations and is frequently also used to clean theworkstations. Individually driven opening rollers, each of whichincludes a separate drive motor, are predominantly used in present-dayspinning machines, however.

An opening device of this type is known from DE 10 2006 033 971 A1. Thispublication deals with an accumulation of fibers that arises in theregion of the sliver feed, in particular due to adhering trash, such asdust, neps or honeydew. To remove the accumulation of fibers, a blowingnozzle unit is to be installed in the circumferential surface of theopening roller housing surrounding the opening roller, in the region ofa housing interstice between the opening roller and the feed cylinder.By means of the air flow that is activated as a result, the trashparticles adhering there are detached. Nevertheless, such individuallydriven opening rollers can result in fibers accumulating, in particularin the region of the card clothing, and thus the opening roller becomingblocked.

SUMMARY OF THE INVENTION

A problem addressed by the present invention is that of providing amethod for operating a spinning station of a spinning machine and anappropriate spinning machine, which avoids an accumulation of fibers andblockages at an individually driven opening roller. Additional objectsand advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

The problems are solved by a method and a spinning machine having thefeatures described and claimed herein.

In a method for operating a spinning station of a spinning machine, inwhich a fiber material is opened into individual fibers by means of anopening unit and the individual fibers are spun into a yarn by means ofa spinning device, the opening unit includes an opening roller, which isrotatably mounted in an opening housing and is drivable by means of anindividual drive. The spinning device is connected to a negativepressure channel of the spinning machine and acted upon by negativepressure. The opening housing is connected to the spinning device via afeed duct.

In the method, it is provided that, during a downtime of the spinningstation, the opening roller is driven briefly at least once and isstopped again by means of its individual drive. In an alternativeembodiment of the method, it is provided that, during a downtime of thespinning station, the opening roller is driven at a minimum rotationalspeed by means of its individual drive. The minimum rotational speed isa rotational speed, which is reduced as compared to the operating speedof the opening roller and with which the opening roller can just barelybe held in rotation. The present invention has determined that fibersthat have become stuck, in particular, at the card clothing of theopening roller, can be detached already by setting one individuallydriven opening roller into motion one time. This is also possible whenthe opening roller is operated during a downtime of the spinning stationat a minimum rotational speed that is greatly reduced as compared to itsoperating speed. With individually driven opening rollers, largeramounts of fibers can accumulate in the region of the card clothing, inparticular during a longer downtime of a spinning station, since aircontaining fibers is constantly sucked in via the supply air openings inthe opening housing even when the opening roller is stopped. The fiberscontained in the air are retained by the card clothing of the stoppedopening roller and accumulate there. These fibers can result in a slowdown and even blockage of the opening roller and prevent a smoothrestart of the spinning station.

By moving the opening roller, fibers can now be prevented from becomingstuck at the card clothing of the opening roller. Fibers adhering to theopening roller can also be detached before the accumulation of fibersresults in blockages. For example, fibers can be detached from theopening roller in the region of the trash removal opening due to theeffect of gravity and, if applicable, acting centrifugal forces, anddiscarded via the trash removal opening. Moreover, the fibers can bedetached by exposing the fibers to a suction flow in the region of thefeed duct, which connects the opening housing to the spinning device, asa result of which the fibers are also detached. A slow down or blockageof the opening roller can be effectively prevented as a result.

The same advantages can also be achieved with a spinning machine havinga multitude of adjacently arranged spinning stations, each of whichincludes an opening unit for opening a fiber material into individualfibers and a spinning device for spinning the individual fibers into ayarn. The opening unit has an opening roller, which is rotatably mountedin an opening housing and is drivable by means of an individual drive,the spinning device being connected to a negative pressure channel ofthe spinning machine and acted upon by negative pressure, and theopening housing being connected to the spinning device via a feed duct.The spinning machine includes a control unit for carrying out the methodaccording to one of the preceding claims. The control unit can be acontrol unit of the spinning station or a central control unit of thespinning machine. The method can also be carried out in cooperation withtwo or more control units. It is particularly advantageous that noadditional structural measures are necessary, and so the spinningmachine can be cost-effectively designed.

It is advantageous when the opening roller is driven counter to itsregular direction of rotation during the downtime of the spinningstation. Accidents resulting due to the opening roller rotating whilethe spinning station is stopped can be avoided as a result.

It is particularly advantageous when the opening roller is brieflydriven and stopped again multiple times at predetermined time intervals.This is advantageous in particular during a longer downtime of thespinning station in order to avoid a larger accumulation of fibers.

It is also advantageous when the time intervals are set in a controlunit of the spinning station and/or of the spinning machine. With thespinning machine, it is therefore advantageous when the opening rolleris drivable at predetermined time intervals, the time intervals beingsettable in a control unit of the spinning station and/or of thespinning machine. As a result, the spinning station can automaticallydetach or prevent an accumulation of fibers that may form withoutoperating personnel and without a movable service device.

It is particularly advantageous when the time intervals are set in anapplication-specific manner depending on the fiber material that is usedor, at the spinning machine, are storable in the control unit and/or ina system control unit having an article management system in anapplication-specific manner depending on the fiber material that isused. As a result, it can be provided that driving is carried out morefrequently, for example, in the case of fiber materials loaded withtrash or coarser fiber materials, in order to manage the greatertendency for fiber to adhere.

It is also advantageous when the opening roller is additionally cleanedby means of a blast air stream, in particular a blast air stream from aspinning station-specific blowing nozzle. In the spinning machine, thespinning stations each have a spinning station-specific blowing nozzlefor cleaning the opening roller. The detachment and/or the removal offibers that have already been detached from the card clothing can beassisted by means of such a blowing nozzle.

It is advantageous when the blowing nozzle opens into the region of thetrash removal opening in order to assist the removal of the detachedfibers.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention are described in the followingexemplary embodiments, wherein, schematically:

FIG. 1 shows a schematic front view of a spinning machine, as anoverview representation,

FIG. 2 shows a spinning station of a spinning machine in a schematic,partially cut side view,

FIG. 3 shows a schematic, partially cut front view of a spinning stationincluding an opening unit according to a first embodiment, and

FIG. 4 shows a schematic, partially cut front view of a spinning stationincluding an opening unit according to a second embodiment.

DETAILED DESCRIPTION

In the following description of the alternative exemplary embodimentsrepresented in the figures, the same reference signs are utilized forfeatures that are identical or at least comparable in terms of theirconfiguration and/or mode of operation. Provided the features are notdescribed in detail again, their design and/or mode of operationcorrespond/corresponds to the design and mode of operation of theabove-described features. For the sake of greater clarity, referencesigns for previously described components have not been individuallyincluded in the figures.

In the following description of the figures, the same referencecharacters are used for features that are identical and/or at leastcomparable in each of the various figures. The individual features,their embodiment and/or mode of operation are explained in detailusually only upon the first mention thereof. If individual features arenot explained in detail once more, their embodiment and/or mode ofoperation correspond/corresponds to the embodiment and mode of operationof the features that act in the same way or have the same name and havealready been described. Moreover, for the sake of clarity, often onlyone or only a few of several identical components and/or features is/arelabeled.

FIG. 1 shows a schematic front view of a spinning machine 1 in aschematic overview representation. The spinning machine 1 has amultitude of adjacently arranged spinning stations 2 in a manner known,per se, the spinning stations 2 being arranged between two frames 3 ofthe spinning machine 1. For the sake of clarity, only two spinningstations 2 are designated and their individual components labeled in thepresent case. Each of the spinning stations 2 includes an opening unit 4for opening a fiber material 5, which has been supplied thereto, intoindividual fibers 6 (see FIG. 2 ). The individual fibers 6 are fed to aspinning device 7, in which the individual fibers 6 are spun into a yarn8. The spun yarn 8 is then drawn out of the spinning device 7 and fed toa winding device 10, where it is wound onto a package 11.

The spinning machine 1 has a central control unit 9 for controlling thefunctions of the spinning machine 1 and/or the spinning stations 2.According to the present representation, the spinning stations 2 eachalso have a spinning station-specific control unit 9, which is connectedto the central control unit of the spinning machine 1, as indicated bythe dotted lines.

Optionally, the spinning machine 1 can also include a service device 22,which is movable along the spinning stations 2. The service device 22also includes a control unit 9, which is connected to the centralcontrol unit 9 of the spinning machine, as is also indicated by a dottedline.

In modern spinning machines 1, the spinning stations 2 of which aredesigned as autonomous spinning stations 2 which can automatically carryout a piecing process also after a thread breakage, such service devices22 are necessary only for carrying out a package change. Most of theother service actions, such as seeking a thread end traveling on thepackage, cleaning the spinning element, preparing the yarn ends, and theactual piecing can be carried out by the spinning stations 2 themselves,which include individually drivable handling units for this purpose. Thepresent invention is preferably usable on rotor spinning machines 1including such autonomous spinning stations 2, although the presentinvention can be used on any spinning machine 1 having an individuallydriven opening roller 15 (see FIG. 2 ).

FIG. 2 shows a spinning station of a spinning machine 1 in a schematic,partially cut side view. The spinning machine 1 is designed as a rotorspinning machine in the present case. As described with reference toFIG. 1 , a fiber material 5 is fed to the spinning station 2. For thispurpose, the spinning station 2 includes a feed roller 16, which feedsthe fiber material 5 to the opening roller 15 of the opening unit 4, theopening roller 15 being rotatably mounted in an opening housing 13. Theopening roller 15 is driven for this purpose by means of an individualdrive 14. The fiber material 5 is opened by the opening roller 15 intoindividual fibers 6, which are then fed to the spinning device 7 via afeed duct 18. The feed duct 18 connects the opening housing 13 to thespinning device 7. The spinning device 7 includes a spinning rotor 12,which is arranged in a housing (not shown), to which negative pressureis applied. The spinning device 7, more precisely, the housing in thiscase, is connected to a negative pressure channel 17 for this purpose.

In the method, during a downtime of the spinning station 2, the openingroller is briefly driven and stopped again at least one time, preferablyalso multiple times, by means of its individual drive 14. The individualdrive 14 of the opening roller 15 is connected for control purposes tothe control unit 9 of the spinning station 2 for this purpose. Thecontrol unit 9 can control the repeated driving of the opening roller 15at predetermined time intervals. For this purpose, the time intervalscan be established in the control unit 9 of the spinning station 2 oralso in the central control unit 9 of the spinning machine 1, forexample, depending on an application of the spinning station 2.Alternatively to repeatedly driving the opening roller 15, it can alsobe provided that driving is carried out permanently during a downtime ofthe spinning station at a rotational speed that is reduced as comparedto the operating speed of the opening roller. As a result, a largeraccumulation of fibers, which can result in blockages of the openingroller, can be avoided and the smooth restart of the spinning station 2can be ensured. This is explained in greater detail in the followingwith reference to FIGS. 3 and 4 .

FIG. 3 shows a schematic, partially cut front view of a spinning stationincluding an opening unit 4 according to a first embodiment. The feedingof the fiber material 5 by means of the feed roller 16 is shown. Thefiber material 5 is opened into the individual fibers 6 by means of acard clothing 20 of the opening roller 15. The individual fibers 6 arealso discharged by means of the card clothing 20 to the feed duct 18,from where the individual fibers 6 enter the spinning device 7 due tothe effect of the negative pressure prevailing in the spinning device 7.The spinning device 7 is designed as a rotor spinning device in thepresent case and includes a spinning rotor 12 as a spinning element.

During operation of the spinning station 2, fiber material 5 iscontinuously fed to the opening unit 4 and the yarn 8 that has been spunfrom the fiber material 5 (see FIGS. 1 and 2 ) is continuously drawn outof the spinning device 7. In spinning machines 1, individual spinningstations 2 are often down for a longer period of time. This is the case,for example, when there is a disruption or a defect of the spinningstation 2 or also when the relevant spinning station 2 has alreadyreached its production target and a new product has not yet beenstarted. Due to the negative pressure applied in the spinning device 7,air is drawn in, also during a downtime of the workstation 2, however,from the supply air openings, in particular the trash removal opening23, in the opening housing 13 through the opening housing 13 via thecard clothing 20 of the opening roller 15 into the spinning device 7.The fibers contained in the air cling to the card clothing 20 of thestopped opening roller 15, as a result of which an increasingly largeramount of fiber can accumulate over time.

If the opening roller 15 is now briefly driven at least one time,preferably multiple times, however, during the downtime of the spinningstation 2, the accumulation of fibers can be effectively avoided. Due tothe brief driving, individual fibers 6 can be prevented from clinging tothe card clothing 20 and individual fibers 6 that are already adheringcan be detached from the card clothing 20. The individual fibers arepreferably detached from the card clothing 20 in the region of the trashremoval opening 23 due to the effect of gravity and can be dischargedvia the trash removal opening 23. Individual fibers 6 in the region ofthe feed duct 18 can also be exposed to the effect of the negativepressure applied there, as a result of which the individual fibers 6 canbe detached from the card clothing and discharged via the feed duct 18.

FIG. 4 shows a schematic, partially cut front view of a spinning station2 including an opening unit 4 according to a second embodiment. Incontrast to the embodiment according to FIG. 3 , a spinningstation-specific blowing nozzle 19 is arranged at the presently shownspinning station 2 for cleaning the opening roller 15. The blowingnozzle 19 is connected to a compressed air supply (not shown here) andis actuatable by means of a valve 21. The detachment of adheringindividual fibers 6 from the card clothing 20 can be assisted by meansof the blowing nozzle 19. Preferably, the blowing nozzle 19 is arrangedfor this purpose closely ahead of the trash removal opening with respectto the direction of rotation of the opening roller 15. The spinningdevice 7 is designed as a rotor spinning device including a spinningrotor 12 in this case as well. The invention is also usable at all otherspinning machines 1, however, the spinning stations 2 of which haveindividually driven opening rollers 15.

The present invention is not limited to the represented and describedexemplary embodiments. Modifications within the scope of the claims arealso possible, as is any combination of the described features, even ifthey are represented and described in different parts of the descriptionor the claims or in different exemplary embodiments, provided nocontradiction to the teaching of the independent claims results.

LIST OF REFERENCE CHARACTERS

-   -   1 spinning machine    -   2 spinning station    -   3 frame    -   4 opening unit    -   5 fiber material    -   6 individual fibers    -   7 spinning device    -   8 yarn    -   9 control unit    -   10 winding device    -   11 package    -   12 spinning rotor    -   13 opening housing    -   14 individual drive    -   15 opening roller    -   16 feed roller    -   17 negative pressure channel    -   18 feed duct    -   19 blowing nozzle    -   20 card clothing    -   21 valve    -   22 service device    -   23 trash removal opening

1-10: (canceled)
 11. A method for operating a spinning station of aspinning machine, wherein the spinning machine includes: an opening unitthat opens a fiber material into individual fibers that are spun into ayarn by means a spinning device; the opening unit including an openingroller rotatably mounted in an opening housing and drivable by anindividual drive, the spinning device connected to a negative pressurechannel of the spinning machine and acted upon by negative pressure, theopening housing connected to the spinning device via a feed duct; themethod comprising: during a downtime of the spinning station, performingone or both of: driving and stopping the opening roller at least onetime by means of the individual drive, or driving the opening roller ata minimum rotation speed by means of the individual drive.
 12. Themethod according to claim 11, wherein the opening roller is drivencounter to an operational direction of rotation during the downtime ofthe spinning station.
 13. The method according to claim 11, wherein theopening roller (15) is repeatedly driven and stopped at predeterminedtime intervals during the downtime of the spinning station.
 14. Themethod according to claim 13, wherein the time intervals are set in acontrol unit of the spinning station or a control unit of the spinningmachine.
 15. The method according to claim 13, wherein the timeintervals are set in an application-specific manner depending on thefiber material being spun at the spinning station.
 16. The methodaccording to claim 11, further comprising additionally cleaning theopening roller with a bast air stream from a spinning station-specificblowing nozzle.
 17. A spinning machine, comprising: a plurality ofadjacently arranged spinning stations, wherein each of the spinningstations comprises: an opening unit that opens a fiber material intoindividual fibers that are spun into a yarn by a spinning device; theopening unit including an opening roller rotatably mounted in an openinghousing and drivable by an individual drive; the spinning deviceconnected to a negative pressure channel of the spinning machine andacted upon by negative pressure; the opening housing connected to thespinning device via a feed duct; the spinning machine or each spinningstation further comprising a control unit configured to control thespinning stations to perform one or both of the following during adowntime of the spinning station: driving and stopping the openingroller at least one time by means of the individual drive, or drivingthe opening roller at a minimum rotation speed by means of theindividual drive.
 18. The spinning machine according to claim 17,wherein the opening roller is drivable at predetermined time intervalsset by the control unit.
 19. The spinning machine according to claim 18,characterized in that the time intervals are stored in the control unitand are application-specific depending on the fiber material being spunat the spinning station.
 20. The spinning machine according to claim 18,wherein each spinning station further comprises a station-specificblowing nozzle for additional cleaning the opening roller.